Thermal barriers and thermal seals are integral components in the thermal protection systems and propulsion systems of many aerospace vehicles. Their primary function is to minimize the flow of hot gases through an interface and protect underlying temperature-sensitive systems and structures. One of the primary challenges with these components is maintaining proper sealing contact at elevated temperatures of greater than 1200° F. Thermal barriers and seals, for example, often lose resiliency at higher temperatures, resulting in an open gap condition between the seal and its opposing sealing surface. This open gap condition allows heat to be ingested with potentially catastrophic consequences, including loss of mission, loss of vehicle, or in the most extreme case, loss of crew.
Further, hypersonic vehicles and propulsion systems require thermal barriers and seals that operate in extreme environments where temperatures exceed 1200° F. At these temperatures, conventional polycrystalline alloys lose strength and exhibit excessive creep. Accordingly, a preloader configured with a thermal barrier or seal to maintain excellent resiliency in excess of 2000° F. may be beneficial. Other potential aerospace applications include variable geometry commercial and military engines for supersonic cruise capability.
In addition to the above uses, preloaders can be utilized in industrial applications in which high temperature seal resiliency is required. This includes seals for furnace doors, high temperature forges, and continuous casting applications.